Roma preserved their outside chance of beating Juventus to the Serie A title with a confident victory at Bologna -- but Sunday's real drama took place at the bottom of the table.
It was straightforward for Roma, who briefly fell nine points behind Juve when the champions defeated Chievo 2-0 on Saturday, as Edin Dzeko capped a 3-0 away win with his 24th goal of the season.
Defender Federico Fazio and Egyptian winger Mohamed Salah had given Roma their healthy half-time lead, and Bologna came closest to responding when Mattia Destro hit a post after the break.
The two Milan clubs were tasked with defeating a pair of teams fighting for their top-flight lives, and their contrasting performances changed the make-up of the relegation battle.
Napoli all but locked Lazio out of the final Champions League place by opening a seven-point gap on their southern rivals with a 3-0 victory in Rome.
Jose Callejon scored a trademark close-range goal midway through the first half, with Lorenzo Insigne thoroughly atoning for a poor miss by bagging a second-half brace for Napoli.
While there are still seven games to play and with them 21 points to fight for, the Azzurri look best placed to finish third given their scoring prowess and superior head-to-head record with Lazio.
However, Simone Inzaghi's men will play three of Serie A's bottom five over the run-in, while Napoli's remaining opponents are mostly mid-table outfits including Torino and Sampdoria.
Inter Milan were at promoted Crotone, who started the day six points shy of 17th-placed Empoli and safety, but a brace from Diego Falcinelli slashed that gap in half.
The on-loan Sassuolo striker converted an 18th-minute penalty and doubled his tally four minutes later, with Inter struggling to respond until Danilo D'Ambrosio made it 2-1 after the hour mark.
At San Siro, AC Milan made light work of 19th-placed Palermo, whose return to Serie B looms large.
There was a Merseyside connection as former Liverpool winger Suso opened the scoring, with Everton loanee Gerard Deulofeu rubber-stamping a 4-0 success after Mario Pasalic and Carlos Bacca had pushed the Rossoneri well clear of any retaliation.
Palermo, who lost Giancarlo Gonzalez to a late red card, remain eight points from survival with only seven games left.
Genoa can still look over their shoulders at the drop zone after going down 3-0 at Udinese.
Rodrigo De Paul and Duvan Zapata had the Bianconeri two goals to the good before half-time and Rubinho's own goal added insult to injury for the hapless Grifone.
Fiorentina twice came from behind to claim a point at Sampdoria -- yet they still lost ground in their bid for European football.
Samp went ahead after just five minutes when Bruno Fernandes struck a brilliant 20-yarder, a lead that held until the hour mark when Gonzalo Rodriguez headed home from a corner.
The hosts reclaimed the lead through Ricky Alvarez 11 minutes later but Khouma Babacar ensured a 2-2 draw when he rifled home in the closing moments.
The result left Fiorentina seven points behind fifth-placed Atalanta.
Elsewhere, Andrea Belotti ensured Dzeko was matched at the top of the scoring charts by reaching 24 for his 2016-17 campaign during Torino's 3-2 victory at Cagliari.
Torino had to recover after falling behind thanks to Marco Borriello's 19th-minute spot-kick opener, but -- once Adem Ljajic had equalised -- the mainlanders had enough confidence to pull away through Belotti and Afriyie Acquah.
Deep into stoppage time, after Acquah had been dismissed for a second yellow card, North Korean substitute Han Kwang-Son replied.